Chimney for enhancing a marginal whirlwind



Jan. 21, 1969 J. VALENSI 3,422,742

CHIMNEY FOR ENHANCING A MARGINAL WHIRLWIND Filed May 9, 1967 INVENTO fiewest kma' B) 7 7 United States Fatent G U.S. CI. 9860 Int. Cl. F23i17/00 4 Claims ABSTRACT OF THE DISCLOSURE A chimney, particularly forland-based and maritime vehicles, of the type having a coveringsubstantially the shape of an aircraft wing, which under the effect ofthe Wind can determine a marginal whirlwind substantially parallel tothe general direction of the relative flow of air around the device.These improvements have the effect of enhancing the formation of themarginal whirlwind starting at the upper end of the cover and in raisingits trajectory to provide the use of a covering of reduced height and ofa thickness which may attain 40% or more of its average length.

This invention relates to improvements for chimneys in order to evacuatefumes, and particularly to chimneys n land-based or maritime vehicles,such as steam locomotives, ships, etc., exposed to a relative wind, soas to prevent the dropping of fumes or smoke on the ships deck. Thepresent invention can also be used to evacuate fumes from industrial orresidential buildings which are exposed to dominant winds of asubstantially single direction.

The French Patent No. 925,303, issued to Jacques Valensi on July 12,1927, for Improvements in Chimneys, Particularly for Land-Based orMaritime Vehicles, provides for creating, in the vicinity of the end ofthe fume conduit or smoke stack of a streamer, a so-called marginalconcentrated whirlwind, in the nucleus or center of which the fume wasreleased. The fume thus was guided or directed to the outlet of the fumeconduit like in a rigid pipe due to the sheath formed by the whirlwind.

According to a preferred embodiment of this invention the fume or smokeconduit was surrounded by a covering having the shape of an aircraftwing, preferably of trapezoidal appearance, and tapered at its end. Thisprovides, under the effect of the relative wind at said end, a marginalwhirlwind substantially parallel to the general direction of therelative flow of air around the device.

The examples described in the Valensi French patent were intendedprimarily for the evacuation of fumes from steamers or ships and appliedmore specifically to the case where one single fume conduit terminatedat the top of the chimney of the steamer, exclusive of any otherevacuation conduit for fumes, vapor or foul air.

These arrangements also required a certain number of precautions whichwill be enumerated below.

(1) The covering must be given sufficient height so that its upper endis placed slightly above the upper limit of the seaways of the shipsuperstructures located ahead of the chimney. Generally, thisrequirement led to a covering having a height at least equal to thelength of its straight section at the base.

(2) The maximum thickness of the wing profile forming the straightsection of this base should not exceed 30% of the length. The form ofthe covering then had to be frustoconical so that the thickness of theconsecutive straight sections of the covering tapers off from the baseto the top.

(3) To avoid the disintegration of the desired marginal whirlwind causedby an incidence of the relative wind on the symmetry plan of the uppercovering at an angle of about 25", special devices, like bafiie plates,blowing or suction slots were recommended.

The improvements according to the present invention relate to a certainnumber of arrangements usable alone or in combination and are applied tochimneys of the kind in question, enhancing the formation of themarginal whirlwind, and increasing or raising the trajectory of thiswhirlwind. These improvements are directed to aiding in preventingundesired dropping of the expelled fumes or smoke on to the ships deck.Using the present invention it is possible to use a covering of verysmall height, whose profile may have a maximum thickness of 40% or moreof the length of its base without destroying the desired marginalwhirlwind at a very high incidence angle (in the order of 50).

The first arrangement consists in providing, at the upper part of thecovering of the chimney, a sealing surface with simple curvature. Thesealing surface is provided with openings for the discharge of thefumes, vapors and foul air from the evacuation conduits, so that saidcovering has live ridges at its upper part.

According to a second arrangement of the invention, the dischargeorifice from the principal conduit for the evacuation of the fumesbisects said surface at a simple curvature along a trapezoidal sectionwhose center is arranged substantially at half the distance between theleading edge and the trailing edge of the curved profile forming theupper part of the covering.

According to a third arrangement of the invention the fume conduit fromthe auxiliary boilers or from the evacuation circuit of the foul airends into an orifice placed ahead of this trapezoidal conduit, havingrectangular shape, with the large base oriented parallel to the verticalsymmetry plane of the steamer and the chimney. The conduit axis of thefume from the auxiliary boilers in the vicinity of the discharge beingpreferably vertical or slightly inclined to the vertical line.

According to a fourth arrangement of the invention the axis of theprincipal conduit of the fume in the vicinity of its discharge is about35 against the horizontal line.

According to a fifth arrangement of the invention the orifices of theevacuation ducts of the vapors or gases are distributed on either sideof said rectangular orifice.

The invention will be better understood from the following detaileddescription thereof taken in conjunction with the accompanying drawingsin which:

FIGURE 1 of these drawings is an elevational view of a covering for achimney according to the invention;

FIGURE 2 is a profile view of the covering shown in FIGURE 1;

And FIGURE 3 is a plan view of this same covering.

FIGURE 1 shows a view in elevation of a covering for a chimney of asteamer or ship provided with the improvements according to theinvention. It is to be understood that the present invention can bereadily adapted to other environments as mentioned previously, and thatthis disclosure is merely for illustration of the invention. As thedescription continues, reference will be made to FIG- URES 2 and 3,where the same reference symbo'ls have been used.

FIGURE 1 shows schematically by a horizontal broken line the upper deckof the ship at the site normally provided for the principal chimney forthe evacuation of the fumes.

On this line reference numeral 1 identifies the front side of the ship,and reference numeral 2 the rear. The side wall 3 of the covering isfrustoconical in shape, and the covering includes a 'base 4 as shown inFIGURE 3.

According to the invention the upper part of the covering is providedwith a simply curved sealing surface 5,

formed by a portion of a cylindrical surface, whose generatrices areperpendicular to the symmetry plane of the covering and bear down on acurve having a substantially parabolic appearance as is shown mostclearly in FIG- URES 2 and 3.

FIGURE 3 shows the different orifices for evacuating the fumes, vaporand foul air, placed into surface 5. The principal orifice '6 for theevacuation of the fumes is, according to the invention, of trapezoidalshape. FIGURE 1 shows that the axis 7 of conduit 8 (in dashed lines)terminating at this orifice forms an angle substantially equal to 35with the horizontal line.

With regard to the arrangement of orifice 6 on the surface it is shownthat the center of the trapezoid is substantially at half way or midwaybetween the leading edge 9 and the trailing edge 10 of the curvedprofile forming surface 5. The discharge orifice 11 of the gases fromthe auxiliary motors is shown in FIGURE 3. This orifice has arectangular shape whose longest side is oriented parallel to thevertical symmetry plane of the ship and the chimney. FIGURE 1 shows thatthe axis 12 of the conduit terminating at orifice 11 is slightly tiltedagainst the vertical line. However, it could also be made vertical ifdesired.

Referring to FIGURE 3, the evacuation orifices 13, 14, 15 and 16 of thevapors or gases are shown as distributed on either side of therectangular orifice 11. The conduits terminating at these orifices havea substantially vertical axle similar to the rectangular orifice 11.

Under these conditions and due to the configuration just described, agaseous vertical vein of relatively small thickness which escapesupstream from the principal fume conduit 8 produces at its downward flowa depression enhancing the discharge of the fumes and raising themarginal whirlwind axis 7.

Furthermore, this escape of a gaseous vein modifies the distribution ofthe pressures along the profiles of the covering in the vicinity of theupper end, resulting in increasing at equal incidence the intensity ofthe marginal whirlwind and preventing its destruction at very greatincidence angles.

It then is possible in accordance with this invention to reduce theheight of the chimney by making it approximately half the profile lineat the base of the covering and increasing its relative thickness,without observing any lowering of fumes on the deck. Thus, theseimprovements have the effect of enhancing the formation of the marginalwhirlwind starting at the upper end of the cover and in raising itstrajectory to provide the use of a covering of reduced height and of athickness which may attain 40% or more of its average length.

FIGURES 1 and 2 shows a certain number of parameters L, l E and H,determining the principal dimensions of the covering. L and lrespectively designate the length of the covering at its base and upperpart; E and e designate the corresponding thicknesses at the base andupper part; and H the height. In an embodiment of evidentlynon-limitative nature, and presented here merely as an example of theinvention, the relations between the different parameters are asfollows: E/L=0.3; e/IEOAO; H/L 0.56.

The foregoing detailed description has been given for clearness ofunderstanding only, and no unnecessary limitations should be understoodtherefrom, as modifications will be obvious to those skilled in the art.

What is claimed is:

1. An improved covering for chimneys of moving vehicles, such as shipsand the like, including a chimney having at least one fume conduit witha discharge end for discharging fumes from said chimney, the improvedcovering compnsmg:

a frusto-conical shaped side wall surrounding said 5 conduit andextending upwardly towards said discharge end; said side wall terminatedin a curved sealing surface having apertures therein aligned with thedischarge end of said fume conduit for discharging the fumes 10 from thechimney through said sealing surface;

sald discharge end of said fume conduit bisecting said curved sealingsurface along a trapezoidally shaped section, the center of said sectionbeing substantially midway between the respective leading and trailingedges of said curved sealing surface; and

said curved sealing surface formed by a portion of a cylindricalsurface, whose generatrices are perpendicular to the symmetry plane ofthe covering and provide a substantially parabolic termination of thefrusto-conical side wall and the curved sealing surface in a plan viewof said covering, for enhancing the formation of a marginal whirlwind atsaid discharge end, thereby increasing the discharge angle of said fumesfrom the chimney towards the vertical axis of said chimney to preventundesired dropping of the fumes onto the ship.

2. The improvement of claim 1, including at least a second fumedischarge conduit having a discharge end aligned with a correspondingaperture in said curved sealing surface, said second fume discharge endintermediate the leading edge of said sealing surface and said firstmentioned discharge end, said second fume discharge end having arectangular shape with the longest sides of said rectangle parallel tothe vertical symmetry plane of said chimney, and wherein thelongitudinal axis of said second fume discharge end is substantiallyvertical.

3. The improvement of claim 1, including an auxiliary boiler conduithaving a boiler discharge end aligned with a corresponding aperture insaid curved sealing surface, said boiler discharge end intermediate theleading edge of said sealing surface and said first mentioneddischargeend, said boiler discharge end having a rectangular shape with thelongest sides of said rectangle parallel to the vertical symmetry planeof said chimney, and wherein the longitudinal axis of said boilerdischarge end is substantially vertical.

4. The improvement of claim 3, including a series of vapor dischargeconduits having respective discharge ends 0 on either side of therectangularly shaped auxiliary boiler discharge end.

References Cited UNITED STATES PATENTS 1,939,254 12/1933 Dyer 9860FOREIGN PATENTS Ad. 62,280 1/ 1955 France. 1,014,104 5/ 1952 France.

261,190 11/1928 Italy.

ROBERT A. OLEARY, Primary Examiner.

MANUEL A. ANTONAKAS, Assistant Examiner.

US. Cl. X.R. 114287 UNITED STATES PATENT OFFICE CERTIFICATE OFCORRECTION Patent No 3 ,422 ,742 January 21 1969 Jacques Valensi errorappears in the above identified It is certified that nt are herebycorrected as patent and that said Letters Pate shown below:

Column 1, line 34, "925,303" should read 945,303 line 35, "1927" shouldread 1947 Signed and sealed this 9th day of December 1969.

(SEAL) Attest:

Edward M. Fletcher, Jr.

Commissioner of Patents Attesting Officer WILLIAM E. SCHUYLER, JR.

